Tire-casing mold.



W. H. BUHRITT.

'URE CASING MOLD.

APPLICATION FILED muze, |915. y

Patented Feb. 6, 1917.

2 SHEETS-SHEET l Wmmsms:

` ATTORNEY;

w. H. Emme TIHE CASING WIGLD. APPLICATION m50 MAR.29,1915.

Patented Feb. 6.1917.

Ez @El IJVVEJYTOR,

WITNESSES:

lillblvllllil) STAT@ WILLIAM H. BURRITT, 0F ST. LOUIS, MISSOURI.

TIBE-CASING MOLD.

Specification of Letters Patent.

Patented Feb. 6, 1917.

Appnation ined Maren 29, 1915. serial No. 17i2.

Be it known that l, lVrLnLs/n H. Bonnrrr, a citizen of the United States, residing at St. Louis, State oi: lilissouri, have invented certain new and useful lnipro'tements in lire-asing llloldt. of which thefollowing is a full. clear, and @met descriptionhreference being had to the accompanying drawings, forming a part hereof.

My invention has relation to improve ments in tilr. .-c:,a,si .r,ig forms or molds; and it consists in the noi'el construction of mold more 'Folly set forth in the specification and iioinled ont in the claims.

The present invention is directed 'to the construction olf 4.forms or molds ,intended to produce. a special design of tire casing, cx- :nnples ot which are to be found in pneumatic tiros whose support does not depend on the presence olf a rigid felly forming an element of the wheel to which the tire is attached. The casing referred to forms a complementary member of the usual outer tread casing, being interposed between said tread casing and the hub of the wheel, and preferably (though not necessarily)- convened toward the rotation axis of the wheel, being disposed interiorly to the outer tread casing, and jointly with the latter serving to protect the inne-r intlatable tube of the tire.

An instance of such inner casing maybe found in the construction of tire `forming the subject-metter of my pending application filed July Q9, 1912, serial number 711,998, the tire into which such a casing as an element enters being supported` between two sets of spokes leading from the hub in two distinct planes spaced a suitable distance apart. The elimination of the usual folly as a supporting member for the' i tire, imposes on the inner casing a distinct function which 1t could not successfully ful llil were it not for the resiliency inherent in the medial portions of the casing, such resiliency permitting the casing to yield,

under either a. load or under impact, in the' general plane of rotation of the wheel, such resiliency' resulting from the formation of the casing on the mold or form which constitutes the subject-niatter of the present application. The invention is susceptible of more than'fa. single form, but whatever guise it may assii'me, the object sought is to pro duce acasing which will possess the attri fbutes.ofela.st icity or resiliencyr throughout its medial portion, permitting the casmg to yield in the general plane of rotation ol' the wheel, under the loud and impact conditions heretofore indicated. The invention inidetail may be best described in connection -with 4the accompanying drawings in which-w Figure 1 is a sidel elevation of one form of mold withn portion of one of the clamps removed, to expose the fabric or r-lnck layers entering into the construction of the cnsing;'

Fig. 2 is an edge view of Fig. 1; Fig. 3 is an enlarged cross-sectional detail on the line 3 3 of Fig. 1, with the clamp on the left, removed; Fig. et is a plan of la short length of the web or fabric snperposed over the mold, showing the manner of application of the fabric to the mold; Fig. is a diagralm matic crosssection through theweb and the peripheral groove of the mold illustrating the manner of the settling of the fabric into the groove, when tension is applied to the fabric inA a direction conforming to s. plane at right angles to the axis o'f the mold; Fig. 6 is a diagrammatic side elevation of a. roll from which the web unwinds and of the form or mold over which it is drawn; Fig. 6 is a diagrammatic cross-section of the complete tire; Fig. 7 is a view on the order of Fig. 1 showing a modified form of mold and clamps therefor; Fig. 8 is an edge view of Fig. 7; Fig. 9 is an enlarged cross-section on the line 9 9 of Fig. 7; and 'Fig'. 10 is a diagrammatic elevation of a series of molds piled one on top of the other during the molding or forming of the casings.

resent two ring sections of a mold or form separable along a pla-ne disposed at right angles to the axis of the mold, the two sections being united by bolts b passed throu h flanges 2 disposed on opposite sidesI of t e planel of separation of the sections. The outer surfgees of the walls of the sections are'eoncated, so 4that when the sections are assembled there"results a peripheral outwardly ooncaved groove or depression d on the -mold ringfthus formed, said depression being bounded by the terminal flanges a the surfaces of whose edges are cylindrically dis osed,(Fig. 3). .il

web or strip of duck or canvas fw such as .usually enters into the composition` of tire casings before vulcanization, will', if

eral plane of disposition of the mold (that is to say in a plane at right angles to the axis of the mold) the medial portions of the web not adhering tothe flanges will gradually yield under the strain imposed on the sides of the web which do adhere to said flanges, and thus yielding, will gradually settle into the depression (Z (see dotted positions of the web in Fig. 5) Where they will adhere more or less to the periphery of the mold. The yielding of the medial portions of thm 'web lw under the conditions as described is characteristic of any web cut on the bias as shown in Fig. 4. If in thus drawing a web or strip over; the mold as indicated we employ a length sullicient to pass around the entire circumference of l'he depression (l (or periphery ot the mold) we would then have a single wrapol duck or its equivalent whose cross-sectional contour would correspolul to the ri-irvature of the cross-section of the der pression al. Having thus secured a single wrap, we can bythe saine method ol. pro cedure secure any number of wraps to produce the required thickness for the eas-ing member desired. lu Fig. 3 for example four web layers are successively wrapped about the form, each layer as wrapped saggingl with its medial portions into the depression d and adhering more or less to the layer which immediately preceded it. ln practice a layer ofA rubber r is lirst deposited in the depression d before4 the web layers are molded thereon in the manner specified. A convenient Way'of applying the web is to have thesame mounted on a rollD whence l it may be drawn over the mold ring 1 (Fig.

6) and wrapped about it in consecutive layers, sections of the web corresponding in length to a single wrap or layer being'ent off from the roll as the successive sections are applied. In the present illustration (Fig. 3) the completed casing W is made up of four wraps of web w, an outer layerof rubber fr, and the side beads h. The latter are attached to the layers fw substantially as follows: After the four Wraps of the webs fw, of the duck or canvas have been deposited and molded in the peripheral depression d, the side edges of the strips lw (which by the way are considerably wider than the mold) are left to project over the outer corners ot' the flanges a, two of the sides so projecting being 'turned inward and two outward (see dotted showing in Fig. 3). Thereupon the beads h are passed over the flanges a, a, and over the base of the. two -outwardly turned projecting sides of the. webs fw, after which the four free edges of the' webs are alternately folded over the bead until the latter is covered bythe fabric, thus incasing the v`bead as fully shown in Fig. 3. This being accomplished there arie passed over the beads L and the. flanges (L supporting thesame, a series ol channel'clainps 3, the inner flange of each clamp being provided with a lateral curved extension 4, the curvature of said extension conforming to the concavity of the depression d and to the concavity assumed.

by the layers of duck to. 'The extensions of lopposing clamps meet along the plane of division between tlie ring sections 1, 1 (Fig. There are four clamps to each'ring l, the terminals of thc clamps being providcifl with lugs 5, through which the several clamps may be bolted or otherwise tied to` gether, and to the ring. I do not wis-l; to be restricted to any number of clamps or clamp sections, as these may be varied. but l .find four to be convenient in prm'tive. 'the clamp sections 'when assembled about the ring` may be regarded as a single clamp encompassing the head fr.. the extension l oi the clamp bearingl outhe casing body lil". The easing' with its beads f1y and outer rubber layer -1 being thus clamped to the. mold (or mold ring), the ring is then 'placed into a vulcanizing chamberand the rubber cow Astituents of the rasing thoroughly vulcan-- ized as well understoml in the art. after which the clamps are detached and the iin ishcd cas-ing rcmcn'ed from the mold.

As previously pointed out, the casing `W Jforms the inner member ot a tire prorided with an outer casing l. the two casings enreloping the inflatable tube 10, and the tire being supported Jfrom the sides by the spokes ll, l1. This form of tire is shown diagrammatieally in. Fig. G and conforms in all essential ).)articulars with the tire forming the subject-matter o'l" my pending application aforesaid.

In the form of mold described, the surface of the deinfessic'in d eoncaves outwardly, the longitudinal medial line thereof ferne ing a circle described by the shortest radius from the axis of the mold as acenter,and the outer corners of the peripheral faces or edges of the flanges a, a, forming circles described by the longest radii from the same center. It thus follows that the crown of the Atransverse arch formed by the depression d and hence the crown of the arch formed by the transverse curvature of the molded casing W will be disposed along a circle described by the shortest radius from the center of the mold, and the outer edges of the bead .formations of said casing will be disposed alongcircles described by the longest radii from the same center. Accordi-ngly, a mold which will produce a casing with these characteristics will be an equiva lent of the forni already described, and in' vthe modification covered by Figs. 7 to 10 in- S ll sis.

with the narrow dimension olf the web aiu-oen the surface nl', the liree edges of the wel.) being brought up along the .aides of the oui-ved aiirl'ace and :ip along the plane iHide terminals e fig.` ll said terminals forming leiflgesi 'lor the deposit, el the heads fl. tirer the beads are passivi the irland/fine' ihaiiiietriiigifeI 21 as shown. 'ihe strips in being ot unil'orni length and width, itfol lowri that iu order to liriugg,- the `Slide edges thereof" to thol'ull iliuienionel o tf' the larger eiriles deliuril hy the side edges of the ringl (or outer edges of the Iei'lges a) the fabric. which is vcut on the bias by the way, inust he stretched cireilinferentially So'that the outer 'portions ol" the finished casing are taut or atreliiiliid, .vheri-aey thel niedial porlione` whii-h are nearer the lauiailer i-irile or 'that deairihial hy the shorter radius are yielding aud elastic, as thi-ee have not bei-n stretched to the point where they" renee to be elastiii. lu the nioililii'at'iou the rubber layer 1' in deposited on lhr outside o l`|ii` iti-.lx railing W, hel'ore the ilaliips il :err ap plied. alter whieii the ring with itA rlaiiipa.y ora series l'iuuiing a pile :is Iahowii diagramiuatii-ally.r in li`ig. IO are placed. in the vul-v iauizinir i'haniher.

it will be seen lroui the foregoing that whether the easing be molded on the forni LShown in Iiilig. $3 or on that i@hewn in liiir. il, the resulting' prodiii-,t will'he siiitli as to possi-,as a' longitudinally yielding.; or elastic: ineilial portion (that ia to say a portion yielding; in the general plane ol' rotation ol the wheel on which the casingr is inally mounted) lor takingup jars or imparte" with the .passage olE the vehicle over rough aurl'aiis, the outer easing (l being in no wise disturbed oi' ilisarranged. 'lhere thus results an eaey riding vehicle as 'fully point-A ed out in iny pending application aforesaid. \\"hi\ther the casingr be molded on :i torni or niolil haring a irieriphiral outwardly ooni'ai'id depression` or on a inold haring an inner converted l'orniatioii, the result is the saine since each eiiri'ed molding lurtare has ite. longitudinal (that is to say i'iriuiii'l'ei'inH tial) medial line defini-d hy a i-iri-le ile-- scribed by a short radius l`roiii the renter ol' the mold (or wheel on which the easing is finally depositei'l), and the `eide edges di fined by circles described h'i' longer radii from the saine eerder; and the reason thatl the stretelfi is not taken out otithe web strips of which the iaeiiig is composed. iii

the regions bori'lcring on .auch niidial line. is because these portions ot the weh heure' nearest to the axis olf the mold, there inno neeese'ity of initially stretchiugg,F the fabric tomaintain said portions at thix point desired. whereas the Sides olE the webs or iatripa1 n'iiist be stretched to bringtheui to. and

wieh to be restricted to a liowid a rih. as the aanie may he lal` that is to say the rose- .sei-tion oli the molding,r surface may approarh that ol" a. channel bar or he U-Hhapeil. .\i-,- eordingly the term arched as used in the i'lainiel must not be taken iu a reatrii'ti-il sense hut ia to be eoustruid broadly lo rover any surface whichnecessitates thil folding of the edges of the weh or lati-ip outwardl \r or away from the axis of the iuold uiiuihiir.

Having described my invention what `I elaiin is:

l. f\ niold o'lT the character described, rouiprisiupr an annular iueiuhir or riut; ha i'- ine' a [muoversi-ly arched'surface l'or the deposit and support ol" the iuatirial to hiI shaped or iuoldi-d, the iintir of thil :ii'i'ih being' nearest the gi'ioiuitriii-eulir ol the ring'. and thi` portiouel ol' the ari-h ou either side nl the iruler thiriol heinel at greater ilistauiehl l'riini said gianni-trie renter` and a zuiuiher detaihiilile l'ioui the riu'i: i'lanipingthe iualerial thus4 supported, to the ring' during vuleanizatiou.

'2. A tire-Casing uiold ol' thil iliaitaeter ilesifrihed, i-.ouiprisirngV an annular luiuihei' or ring having' a transversely ari'hiil surl'aeo l'oi the deposit ot the `uialerial yto -he lS'haped or uioldeil, the ieutiif ol' the ari'li living' nearest the geometric center ol" the ring, annular 'l'prnialious adjacent. the edges 'olf' said surrtare for the support ol heads forming coinpoueit. parthl of the rising` aiiil clamps aihipted to pass over the heads thus supi ported for holding the latter to their siip porting,r slurl'aiies duriii;v the vulcanizing procese.

il. A tire-easing' inold of the character desilribeil, comprisingr an annular'iiiianher or ring havinga ti'aiisvirsel-v arched surfae 'lior the deposit of the material to he shaped or molded, the center ol' the arr-h beingl nearest the geometric center of the ringfannular foriuatious on the sides of the arched Suf'- lace for the support ot' heads forming component uieiubere ot' the linislied easing, and

clamps operating-to hold the beadsto said- 'lorinations and the material to the slipport-- ing' t'aee aforesaid.

l. :X tire-casing mold comprising a ring provided with a peripheral transversely arched depression for the support of the. material to he molded, [langes bounding the .aides el said depression and projecting radially beyond the surface of Saididepression, thel peripheral faires orV edges of the flanges l'orniine' supporting' surfaces for the head rouipouents ol the casing, and sectional an'- uiilar channel clamps passed over the beads thus supported and spanning the sides of the llanges, the inner flange of the clamp v being -provided with an extension curved to conform to the material molded on the surface of the peripheral depressonaforesaid, and hold the said material to the mold during vulcanization of the tire.

5. A mold ring for tire casings provided with a peripheral external conca'ved depression and bounding bead-supporting formations disposed on the sides of said depression, in combination with members operating to encompass the beads and same to the formations aforesaid.

6. A mold ring for tire'casings provided With a transversely arched 'surface bowed toward the axis of the ring and bounding bead-supporting formations disposed at the sides'of said surface, in combination with sectional, annular, channel members operating to,hold the beads to the formations aforesaid.

7. A mold ring for tire casings provided with a transversely arched surface bowed toward vthe axis of the ring and bounding bead-supporting formations disposed at the sides ofsaid surface, in4 combination with annular channel members operating to hold the beads to the formations aforesaid.

hold the 8. In combination with a marginally andy peripherally fianged mold ring, an annular sectional channel clamp adapted to be detachably passed over the flange and pro .vided with a lateral extension leading from the inner flange of the channel across the material deposited on the peripheral surface of the ring beyond the flange thereof,

and means on the clamp sections for drawing the sections tightly about the ring.

9. A tire-casing mold provided with an annular transversely arched surfacebowed toward the axis of the. mold for the support of the material, and having suitable side beadsupporting formations, in combination with detachable annular channel clamps operating to span the beads to the formations aforesaid.

10.'A tire-casing mold provided with an annular transversely arched surface bowed toward the axis of the mold for the support of the material, and having side bead-supportingv formations, in combination with means for engaging the beads and holding them to said formations.

1l. In combination with a marginally and peripherally anged m'old ring having a, transversely arched surface bowed toward the axis of the ring, a channel clamp adapted to be passed over the flange of the ring and provided with a lateral extension leading from the channel across the arched surface of the ring and engaging the material deposited on said surface. y

In testimony whereof l alix my' signature, in presence of two witnesses.

WILLIAM H. BURRITT. Witnesses EMIL FRANK, ELSE M.VSIEGEL.

and hold the samev 

